Added QuaMeter IDFree mode in TraIT Proteomics QC Pipeline. 

run_msqc_pipeline.py: 
1) Added variable _QUAMETER to specify QuaMeter installation folder. 
2) Added definition _run_quameter_idfree(...).
3) Added pipeline stage 5 - _run_quameter_idfree(...).

parse_metrics.py: 
1) Added variable quameter_metrics_file to specify QuaMeter output TSV
file. 
2) Added definition _extract_quameter_idfree_metrics(...) to extract
QuaMeter metrics from the TSV file. 
3) Added list metrics['QuaMeter'] to hold QuaMeter metrics.
4) Verified that QuaMeter metrics are written and saved in the
Metrics.json file.